With the increasing importance of packet services, both from a traffic and economic perspective, the telecommunications industry is looking for ways to improve the end-to-end efficiency of packet switched networks. One of the most promising approaches in the wide area network (WAN) and metro environments is through closer integration between the packet switching layers and the DWDM layers.
Integration of Dense Wavelength Division Multiplex (DWDM) transponders into packet switching equipment, flexible DWDM network components, and the use of a control plane, such as G-MPLS, collectively known as “Agile DWDM”) to build optical light paths between packet switches are fairly new concepts. Challenges with this new paradigm include ensuring that the packet switch nodes can detect when a new optical link has been established, determining parameters of the remote packet switch nodes, and placing the correct packet switching configuration on the optical link so the two packet switches can communicate at the packet level. Examples of such packet switching networks include Internet Protocol (IP), IP/Multi-Protocol Label Switching (MPLS), MPLS-Transport Profile with a Generalized MPLS control plane, and Carrier Ethernet networks that use Shortest Path First (SPF) based protocols, e.g., Transparent Interconnect of Lots of Links (TRILL) and Institute of Electrical and Electronics Engineers (IEEE) 802.1aq.